tests/vm: use -o IdentitiesOnly=yes for ssh

When one has a lot of keys in ~/.ssh directory, the ssh command will
try all of them before the one specified on the command line, and this
may cause the remote ssh server to reject the connection due to too
many failed authentication attempts.

Fix by adding -o IdentitiesOnly=yes, which makes the ssh client
consider only the keys specified on the command line.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20221027113026.2280863-1-iii@linux.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20221027183637.2772968-31-alex.bennee@linaro.org>

tests/vm/basevm.py

@@ -233,7 +233,8 @@ def _ssh_do(self, user, cmd, check):
                    "-o", "UserKnownHostsFile=" + os.devnull,
                    "-o",
                    "ConnectTimeout={}".format(self._config["ssh_timeout"]),
-                   "-p", str(self.ssh_port), "-i", self._ssh_tmp_key_file]
+                   "-p", str(self.ssh_port), "-i", self._ssh_tmp_key_file,
+                   "-o", "IdentitiesOnly=yes"]
         # If not in debug mode, set ssh to quiet mode to
         # avoid printing the results of commands.
         if not self.debug: